Piggyback a 244 on top again and just solder the 5v and Gnd pins to the
chip below, that will hold it in place and is easily removable in the
future.
Finding the actual fault will probably take longer than its worth, you
could be kind on the next person who looks at the pcb in the future if
you put a string tag on the pcb noting the bodge and its location.
Andrew Welburn
http://www.andys-arcade.com
On 22/08/2012 15:41, Kevin Moore wrote:
> Not sure this went out on the list yesterday. I was having some issues..
>
> Anyways, back to my previous posts on the Tie fighter issues.
>
> I got some time to sit with it, and found something interesting which
> I'm not sure what to make of. I started using my bug trap to look for
> issues, and when I put it on 6h part of the matrix processor counter the
> problem goes away. Its an ls191 I didn't see any fault light come up on
> the bug trap but went ahead and replaced. The original ls191 checked OK
> and the problem still occurs. It will go away if I put the bug trap on.
> So I started checking other chips that had db0 and db1 coming out. I
> piggybacked the ls244 on 4j the problem went away, so I replaced it and
> check again. Problem still present. If I piggy back the ls244 again no
> problem.
>
> The only things that are common between the two chips are db0 and db1 so
> I believe there is a problem somewhere on the DB buss.
>
> Another observation. The problem doesn't occur when the +5 is lower than
> 5, 4.9 seems to be just fine. But 5.04 no good.
>
> Is there an easy way of finding out which chip doesn't like above +5 or
> should I just run it at lower than normal +5 ?
>
> Kevin
>
>
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Received on Sun Aug 26 11:52:02 2012
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